MONACA – The governor says an oil company’s decision on whether to build a proposed petrochemical plant in Western Pennsylvania may be pushed back into next year, but he remains optimistic about the plant coming to the commonwealth.

Gov. Tom Corbett told the Pittsburgh Business Times Friday that he “never had June as a date” for Shell Oil Co. to decide on the multibillion-dollar plant proposed for Beaver County.

“I’ve always thought it would be early next year,” Corbett said, adding that his conversations with officials indicate “they’re still moving forward.”

The June 30 deadline stems from a six-month extension Shell negotiated at the end of last year with Horsehead Corp., which would sell its land 35 miles north of Pittsburgh to the energy firm. The Potter Township site is now home to a zinc shelter, which Horsehead expects to shut down.

The so-called cracker plant would convert natural gas liquids from the Marcellus Shale into more profitable chemicals such as ethylene, which is used to make plastics, antifreeze and other products. Officials have said the plant would employ 100,000 temporary construction workers and provide 400 permanent jobs after that.

While other such plants are moving forward on the Gulf Coast, Corbett says a plant here would be closer to the natural gas source, and the region doesn’t usually get the hurricanes and tornadoes seen further south.

Last year, Shell announced that it had signed a land option agreement with Horsehead to evaluate the site after Pennsylvania had competed with Ohio and West Virginia for the tentative commitment. In addition to making it eligible for at least 15 years of property tax exemptions, Corbett and state lawmakers ensured the Shell plant would be eligible for a 25-year state tax credit of a nickel per gallon of ethane used beginning in 2017. The tax incentives could easily surpass $1 billion in value.

Other officials have also expressed optimism about the plant eventually landing in Western Pennsylvania.

“Natural gas development represents a once-in-a-generation opportunity to create jobs across Pennsylvania and grow our economy,” said U.S. Sen. Bob Casey, D-Pa.